CN101809418A - High performance architecture for process transmitter - Google Patents

Abstract

A process transmitter (200) comprising: at least one sensor (202) monitoring a process variable; and an analog-to-digital (a/D) converter circuit (204) coupled to the at least one sensor and configured to provide process variable data indicative of a value of the process variable. A Digital Signal Processor (DSP) (210) is coupled to the a/D converter circuitry (204) to receive the process variable data. The DSP includes a co-processor (215), the co-processor (215) configured to receive process variable data from the a/D converter circuitry (204) and perform calculations on the process variable data to produce output data. Communication circuitry (250, 280) of the process transmitter is configured to control communication over loop wiring (145) that can be coupled to the process transmitter or to control wireless communication with the process transmitter. A microprocessor (230), separate from the co-processor of the DSP (210), is coupled between the co-processor (215) and the communication circuitry to control movement of output data from the DSP to the communication circuitry.

Description

The high performance architecture that is used for process transmitter

Background technology

Usually, process transmitter comprises process variable sensor and the metering circuit that is used for measuring process correlation parameter (temperature, pressure, flow rate, volume etc.).Process transmitter also comprises output circuit, and this output circuit is used for procedure parameter output is transferred to instrumentation and opertaing device.This transmission is normally carried out on mimic channel, for example is the 4-20mA current return that needs analog output circuit.In addition, for process transmitter, use impulse output circuit to come the process of transmitting relevant information usually, this impulse output circuit sends pulse on current return or digital telecommunication circuit, thereby sends digital signal on the 4-20mA current return.

It is the common architecture at center that great majority " intelligence " process transmitter is shared with the microcontroller.Requirement for microcontroller is very high, and this is because microcontroller must be worked under micropower (typically 1mA) demand usually; Microcontroller must read, handle and announce that sensor upgrades with regular speed; Microcontroller must provide correction function with the main sensed variables of compensation at various error sources usually; Microcontroller must be supported digital communication functions; And microcontroller must be carried out and the management diagnosis activity, to guarantee the accurate operation of process transmitter.The implementation of system that satisfies the demand of all these aspects makes the resource of modern microcontroller bear heavy burden.These resources are divided into 3 classes: power consumption, storage space and execution time.

The microcontroller technology is improved in recent years, provides more ability than previous existing technology.As if yet product demand and market demand have surpassed the development of microcontroller technology.Follow-on process transmitter product may need for example higher speed, more perfect correcting algorithm, multivariate support and high level diagnostics.Usually, conventional procedure transmitter framework only allows progressively improvement to support these demands, may fail to reach the demand of following process transmitter.

Above-mentioned discussion only provides for general background information, is not the scope that is intended to be used to help to determine claimed theme.

Summary of the invention

A kind of process transmitter comprises: at least one sensor, process variable is monitored; And simulation is coupled to described at least one sensor and is arranged to the process variable data that the expression process variable value is provided to numeral (A/D) converter circuit.Digital signal processor (DSP) is coupled to this A/D converter circuit with the receiving course variable data.This DSP comprises: coprocessor is arranged to from A/D converter circuit receiving course variable data and also carries out about this data computing, to produce output data.The telecommunication circuit of process transmitter is arranged to the communication in the control loop wiring or the radio communication of control and process transmitter.The microprocessor that separates with the coprocessor of DSP is coupling between coprocessor and the telecommunication circuit, to control moving of output data from DSP to the telecommunication circuit at the communication in the wiring of radio communication or loop.

Description of drawings

Fig. 1 shows the block diagram of the process transmitter framework of prior art.

Fig. 2-1 shows the block diagram of the first disclosed process transmitter framework.

Fig. 2-2 shows the block diagram of the wireless embodiment of the first disclosed process transmitter framework.

Fig. 3 shows the block diagram of the second disclosed process transmitter framework.

Fig. 4 shows the block diagram of the 3rd disclosed process transmitter framework.

Fig. 5 shows the block diagram of the 4th disclosed process transmitter framework.

Fig. 6 shows the block diagram of the 5th disclosed process transmitter framework.

Fig. 7 shows the block diagram of the 6th disclosed process transmitter framework.

Fig. 8 shows the block diagram of the 7th disclosed process transmitter framework.

Fig. 9 shows the block diagram of the 8th disclosed process transmitter framework.

Embodiment

As shown in Figure 1, great majority " intelligence " process transmitter is shared is the common architecture at center with the microcontroller.As shown in the synoptic diagram of the circuit of theprocess transmitter 100 that provides at Fig. 1, the framework of conventional procedure transmitter comprises: one or moreprocess variable sensor 105; And corresponding simulating is used for converting analog sensor signal to representational digital signal to numeral (A/D) converter 110.Typically, process transmitter also comprises: non-volatile (NV)memory assembly 115 is used for process variable or other information during thestorage operation.Microcontroller 120 communicates with A/D converter 110 andmemory assembly 115 by bus (as, serial peripheral interface (SPI)bus 125).Thespi bus 125 and the corresponding SPI agreement that can be used for the communication between main equipment (for example, microcontroller 120) and the slave unit (for example, A/D converter 110,memory assembly 115 etc.) are well known in the art.Although the disclosed embodiments have been set forth in the use with reference to spi bus, yet the disclosed embodiments are not limited to use with spi bus and SPI agreement.On the contrary, can realize using the communication of additive method, for example, use many main equipments series machine bus I²C or Universal Asynchronous Receiver Transmitter (UART).Except management and control with such as the communicating by letter of A/D converter 110 andmemory assembly 115 equipment such as grade,microcontroller 120 is typically execution and sensor and the process variable function associated that senses also, as, read and processing procedure variable signal, signal correction, diagnostic function etc.

As shown in Figure 1,traditional process transmitter 100 also typically comprises: the numeral that is subjected tomicrocontroller 120 controls is to simulation (DAC)circuit 130, be used for providing control signal successively the 4-20mA signal on output control circuit 135 (for example via output circuit 140) the control procedure control loop to output control circuit 135.Make withdashed lines 145 represent the process control loop that is coupled with process transmitter.Typically,process transmitter 100 also comprises:adjuster circuit 147, reception comes the electric power of the assembly power supply that is used to transmitter of self-loop 145.In addition, typically under the control ofmicrocontroller 120,process transmitter 100 comprises that digital communication protocol (for example,

) modulator-demodular unit 150, this digital communication protocol modulator-demodular unit 150 is communicated by letter withoutput control circuit 135, to use digital communication protocol by 4-20mA loop transmission of digital signals.In addition, can also use the wireless transmission of digital signal, rather than transmit by the 4-20mA loop.

As can be seen, be very high for the requirement of microcontroller because typically microcontroller must satisfy a plurality of demands, provide as example here but be not be expressed as absolute, the demand that is comprised in for example following tabulation:

Micropower operation (below 1mA).

Real time operating system: microcontroller must read, handle and announce that sensor upgrades with the speed (for example, typically every 45mS) of rule.

Signal correction: the microcontroller read sensor information is also carried out correcting algorithm, to compensate master variable at various error sources.

Digital communication: all smart machines (for example, are supported digital communication protocol

Communication protocol).This makes microcontroller bear the heavy burden of acceptance and acknowledge message, composition response and announcement.

Diagnostic activities: controller must manage diagnostic activities, and this diagnostic activities has been guaranteed the accurate operation of equipment.

As mentioned above, the system's implementation that satisfies in the process transmitter of demand of all these aspects makes the resource (for example, power consumption, storage space and execution time) of modern microcontroller bear heavy burden.Consider that the process transmitter product demand has exceeded the improvement of microcontroller technology usually, disclose different process transmitter frameworks, the performance raising that these process transmitter frameworks allow has exceeded the admissible performance of microcontroller technological improvement and has improved.These process transmitter frameworks for example help to provide faster speed (for example, 20mS renewal rate), more perfect correcting algorithm, multivariate support and high level diagnostics under the situation of Power Limitation being no more than.

Term " DSP " (digital signal processor) refers to the technology of the broad range that numeral (scale-of-two) signal is operated.Its implementation is typically towards hardware, yet also can use the software of being carried out by microcontroller to realize.Using the advantage of hardware approach is to realize calculating operation more efficiently than software approach.For this reason, there are many available finished product hardware DSP products.Yet the overwhelming majority of these products is applicable at a high speed, the high power environment, and current drain can easily surpass 100mA under such environment.Since these equipment be designed to fast turn-around (for example, 100MHz), so these equipment typically do not allow its power/performance to zoom to the desired power level of process instrument of loop power supply.

In example embodiment, using DSP, this DSP is mixing of the software operated in hardware and the coprocessor of operative algorithm.This has at the advantage of the lower-wattage of hardware realization (is cost with the dirigibility) and the advantage that dirigibility is provided and is convenient to carry out easily the software of renewal process.The example of this mixing DSP framework comprises the flowmeter dsp chip, the coprocessor that this flowmeter dsp chip uses the hardware filtering device and disposed by software.In the present embodiment, hardware can be used to realize polynomial equation, and this polynomial equation is according to determining pressure at the temperature value and the A/D converter value of employed various sensors.In these equations, it is changeable only needing coefficient, and this can use register to handle.

Fig. 2-1 shows the block diagram that uses first framework to improve the process transmitter 200-1 of transmitter performance.In Fig. 2-1, illustrated and be used for threesensors 202 that process is monitored, yet this embodiment and other embodiment are not limited to the sensor of any concrete number.For example,sensor 202 can be differential pressure (DP) sensor, pressure (P) sensor, temperature (T) sensor etc.Eachsensor 202 is coupled to A/D converter 204, and A/D converter 204 converts sensor output to digital value.Each A/D converter 204 is coupled todigital signal processor 210 via sheet choosing (CS) line, interruption (INT) line and serial peripheral interface (SPI) bus.When A/D converter 204 has the sensor information of renewal, these A/D converters 204 produce interruption on the INT line, after being used corresponding CS line options byDSP 210, selected A/D converter 204 is sent to DSP with the sensing data that upgrades by spi bus.Each A/D converter 204 slave unit will have independent CS line (for example, CS1, CS2 and CS3) and independent INT line (for example, INT1, INT2 and INT3), but can share spi bus.After this, for the sake of simplicity, these lines are referred to as CS line and INT line, but it must be understood that, will use different CS lines and INT line usually.

In conventional procedure transmitter framework, microcontroller (as, microprocessor 230) control pick-up data processing (for example, calculate, compensation or the like) function and come the communication function of transmission sensor related data by the two wires process loop.And different with this conventional architectures, in the framework that in Fig. 2-1, uses, independent DSP 210 is placed betweenmicroprocessor 230 and the A/D converter 204.DSP 210 carries out sensor interface function (for example, handle and interrupt and the receiving sensor data) and sensing data computing function, andmicroprocessor 230 is carried out the circuit communication function.

DSP 210 reads the value that A/D converter 204 provides by spi bus, and these values are stored in the input data register 212.Coprocessor 215 among the DSP 210 calculates output valve then, these output valves is stored in theoutput data register 217, and creates interruption towardsmicroprocessor 230, and thismicroprocessor 230 has related storer (for example, E²Or FRAM storer).Usually, will provide microprocessor access by DSP 210, to avoid timing problems and bus contention problem to A/D converter.

Incase microprocessor 230 receives the sensor information that DSP 210 is calculated,microprocessor 230 just uses digital communication modulator-demodular unit and/or digital to analog converter (DAC) to come data transmission on the control procedure loop 145.In an illustrated embodiment, digital communication modulator-demodular unit and DAC are merged in the single communication circuit chip 240.Yet, in other embodiments, use independent digital communication modulator-demodular unit and DAC chip.With monolithic form the expression of these circuit is not limited to the disclosed embodiments this configuration.The HART modulator-demodular unit that the example of digital communication modulator-demodular unit is to use HART communication protocol to communicate on two wires process loop 145.Circuit communication also can be realized by other industry standard communication protocols.The example of the industry standard communication protocols that is fit to includes but not limited to:

FOUNDATION^TMFieldbus, Profibus-PA and controller local area network (CAN).In the accompanying drawings the digital communication modulator-demodular unit is expressed as

The form of modulator-demodular unit only is an example, the disclosed embodiments can't be limited toCommunication protocol.

Wave filter 245 is coupled to the 4-20mA circuit and the filtering DC component of process loop, and making can be right

The frequency shift keying that uses in the communication (FSK) signal is analyzed.DAC is used for controllingoutput circuit 250, and thisoutput circuit 250 is provided with the 4-20mA electric current on the loop 145.The digital communication modulator-demodular unit is used for sending digital signal viaoutput circuit 250 on current return.For example, use CS and spi bus circuit to realize and the communicating by letter of digital communication modulator-demodular unit or DAC.In addition, for the digital communication modem portion oftelecommunication circuit 240, the circuit of the transmission data (TXD) betweenmicroprocessor 230 andtelecommunication circuit 240/reception data (RXD) also is used for the transmission or the reception of control figure data.Betweencircuit 240 andoutput circuit 250, provide to send data line and signal (TXA),, thereby be convenient to digital communication on the loop with controlling output circuit.Can provide 1 bit signal MSB (for example, the highest significant position signal) to outputcircuit 250 from the DAC part of telecommunication circuit, this signal is the pulse number modulation (PNM) signal, with the control loop current level.

The communication function on the manipulation process loop,microprocessor 230 is also controlled other communication functions, as, controller local area network (CAN) communication.In the embodiment shown, SPI to CAN communication chip uses INT, CS and spi bus circuit to communicate betweenmicroprocessor 230 and CAN equipment.In addition,microprocessor 230 communicates with diagnosis A/D converter 270, and this diagnosis A/D converter 270 is used to diagnose the safe operation with supervisory system.In example embodiment, A/D 270 is 10 bit devices that combine with temperature (board temperature) on monitoring loop current level, supply voltage level, reference power and other voltage and the plate and use.

In the framework that process transmitter 200-1 uses,microprocessor 230 is not born processing and is measured the A/D interruption of passage and sensing data is calculated these task with traditional.The ground that replaces,microprocessor 230 is used for communication or system's control by main reservation.This is particularly useful, because under the situation of the low-power level that can be used by the process transmitter ofprocess loop 145 power supply, master microprocessor is difficult to get caught up in faster sampling rate (cause interrupt rate faster, or the like).

Fig. 2-1 shows and is configured to the process transmitter that communicates by the process control loop.Yet other embodiment also can be configured to carry out radio communication with pulpit, other process devices or with general other equipment.The example of the process transmitter 200-2 of this radio communication is provided in Fig. 2-2.Process transmitter 200-2 has the identical framework of framework with process transmitter 200-1 shown in Figure 1, and difference is to transmit by the process control loop assembly of data.For example, because process transmitter 200-2 does not communicate (perhaps at least not merely like this) by the process control loop, sooutput circuit 250 does not need to comprise in all embodiments.Similarly, can omitcommunication circuit chip 240 andHART wave filter 245, perhaps can make its any necessary function be implemented in other places, for example, be implemented in thewireless communication module 280, thiswireless communication module 280 can substitute the assembly relevant with circuit communication from process transmitter 200-1.If not only needed radio communication but also needed communication by the process control loop, thencommunication module 280 for example can comprise assembly 240,245 and 250, and can be connected tomicroprocessor 230 separately.

According to application,wireless communication module 280 can be suitable for communicating according to any suitable wireless communication protocol, these wireless communication protocols include but not limited to: radio network technique (as, IEEE 802.11 (b) WAP and by Linksys of Irvine, the wireless networking device that California makes up), honeycomb or digital internetworking (as, Aeris Communications Inc.ofSan Jose, California's

), ultra broadband, global system for mobile communications (GSM), GPRS (GPRS), CDMA (CDMA), spread spectrum, short message passing service/communication of text messages (SMS) or any other suitable wireless radiofrequency technology.In addition, can adopt known data collision technology, make adopt a plurality of process transmitters of radio-frequency communication module 280 and/or handheld field maintenance tools can coexist and be operated in each other the radio operation scope.This collision prevents to comprise a plurality of different radio-frequency channels and/or spread spectrum.In addition,communication module 280 can be commercial available bluetooth communication.In the embodiment shown in Fig. 2-1,communication module 280 is the assemblies that are coupled to the antenna (not shown) in the transmitter 200-2, and this antenna can be inside antenna or exterior antenna.In other embodiments,module 280 can be in the outside of transmitter 200-2.

For illustrative purposes, remaining process transmitter embodiment is shown the process transmitter (for example, wired embodiment) of the type that is coupled to the process control loop and communicates via the process control loop.Yet, it must be understood that each among these embodiment all should be interpreted as also comprising corresponding wireless communication procedure transmitter embodiment.In these corresponding wireless embodiment, and can be replaced bywireless communication module 280 by the relevant circuit of the communication of process control loop (shown in corresponding wired embodiment).In addition, because the common architecture that is adopted for the purpose of discussing, hereinafter is referred to as process transmitter " 200 " with process transmitter 200-1 and 200-2, Fig. 2-1 and Fig. 2-2 are referred to as " Fig. 2 ".

Fig. 3 shows the block diagram ofprocess transmitter 300, and thisprocess transmitter 300 uses framework very similar second framework used with process transmitter shown in Figure 2 200.In this framework,microprocessor 230 is removed from the data routing that is used for the 4-20mA electric current on the control procedure loop 145.In order to realize this point, directly drive the output DAC part oftelecommunication circuit 240 from DSP 210.As can be seen from Figure 3, CS and spi bus are coupling betweenDSP 210 and thetelecommunication circuit 240, so that this data routing.This make from A/D converter 204 send pressure data the time be carved into the stand-by period in the moment that simulation output is updated and shorten; Because in transmitter, need communication seldom.Still pass throughmicroprocessor 230 to modulator-demodular unit (for example referring to the TXD/RXD circuit) with the digital communication of the digital communication modem portion ofcircuit 240, with the digital communication ofCAN interface 260 too.

Fig. 4 shows the block diagram of process transmitter 400, process transmitter 400 uses and Fig. 2 and process transmitter 200 shown in Figure 3 and 300 the 3rd similar framework of framework.Process transmitter 400 for example has several respects different with process controller 300.The first, process transmitter 400 comprises the additional special IC (ASIC) of the form with communication module 420.Communication module 420 is to carry out the single ASIC of following function: from the digital communication of telecommunication circuit 240 (for example, HART) modulator-demodular unit,wave filter 245, SPI toCAN interface 260 and CAN power circuit.In addition, as make with dashed lines represented, in certain embodiments, system diagnostics A/D converter 270 can also be embodied as the part ofcommunication module 420.

In order to allow that these function combinations from different circuit units are becomesingle communication module 420, DAC function and the digital modems functional separation fromtelecommunication circuit 240, this allows to realize the digital modems function in communication module.Can realize the DAC circuit in any other place with independence (stand alone) integrated circuit (IC) when needed then with replacing.In the embodiment shown in fig. 4, addDAC circuit 415 to DSP 410, DSP 410 directly communicates by letter with 4-20mA output circuit 250 with the 4-20mA electric current in thecontrol loop wiring 145 then.Except being to comprise theDAC 415 that with DSP 210 difference parts DSP410 can also omitoutput register 217 alternatively because the DAC controlling value is directly to offeroutput circuit 250, rather than bymicroprocessor 230 by interrupting handling.

Fig. 5 shows the block diagram of theprocess transmitter 500 that uses the 4thframework.In process transmitter 500, the A/D converter that is coupled tosensor 202 only comprises artificial circuit part, and does not comprise the digital circuit decimation filter that (for example, in A/D converter 204) realized in A/D converter usually.As directed, a plurality of A/D converters are merged in the single chip 504.Yet, represented as dotted line, can replace A/D converter 504 is embodied as the chip of separation.Each A/D converter provides its sensor coherent signal being coupled on a pair of high-speed data (HSD) the 1 Bit data line of DSP 510.

Realized that with above reference DSP 410 shown in Figure 4 theDSP 510 of the function that the function described is similar has realized being used for thedecimation filter 515 of A/Dfunction.Decimation filter 515 has been created many bit words (for example, 24 bit words) of expression sensor values.For this reason, decimation filter generates long word by carrying out down-sampling with lower frequency, converts high speed 1 bit signal that provides on the HSD line to many bit words.Then, as among the embodiment formerly, many bit words that the down-sampling by decimation filter can be produced are stored in the input register 212.Can compriseSPI communication register 520, thisSPI communication register 520 is used to store the data that will transmit as input and/or output register on one or more spi bus.As directed, this embodiment is not necessarily need be at the output register of DAC, becauseDAC 415 can be directly obtained data necessary from thecoprocessor 215 of DSP 510.Yet, for this purpose or other purposes, for example allowmicroprocessor 230 to read to be used to test, the value of diagnosis etc., can comprise the DAC output register.For example, show this point in the embodiment shown in fig. 8, and following will describing in further detail.

In some optional embodiment, as directed,microprocessor 230 and A/D converter 504 can for diagnose, dispose or other purposes in direct communication each other.By inprocess transmitter 500, adding INT, CS and the spi bus circuit that A/D converter 504 is linked to each other withmicroprocessor 230, be convenient to carry out this communication.In addition, can be alternatively addscrambler 506 anddemoder 508 so that the secure communication between the remainder of A/D converter 504 and process transmitter, rather than (or in addition) use HSD line is communicated by letter between A/D converter 504 and DSP 510 to process transmitter.

Inprocess transmitter 500, can use three or more ASIC configurations that simulated assembly is separated fully with digital assembly.The decimation filter function that employing is addedDSP 510 to other digital functions can be used littler geometry at digital assembly, and can obtain littler power consumption.This is important factor, because process transmitter manufacturer attempts adding increasing function to their equipment, still is subjected to the restriction of the equal-wattage limit simultaneously.

Fig. 6 shows the block diagram ofprocess transmitter 600, and thisprocess transmitter 600 uses the 5th similar framework of framework withprocess transmitter 500, but it is integrated to have an other IC.As can be seen from Figure 6, output ASIC or communication module 420 (can comprise A/D converter 270) merge to formhybrid ASIC 604, because the two all is a hybrid apparatus with A/DASIC 504.In addition, DSP ASIC 510 is merged into individual digit DSP ASIC610 with system'smicrocontroller 230, because the two all is pure digital device.This framework may use available techniques best.Best " numeral " process can be used for DSP ASIC 610, and best " hybrid " process can be used for A/D ASIC 604.

Fig. 7 shows the block diagram ofprocess transmitter 650, and thisprocess transmitter 650 uses and the 6th similar frameworks of above-mentioned framework, but it is integrated to have an otherIC.In process transmitter 650, usesingle ASIC 660 to realize A/D converter, DSP, microprocessor and communication module.In example embodiment, unique assembly that is not implemented in thesingle ASIC 660 issensor 202,output circuit 250 and optional external memory devices 232.Framework shown in Figure 7 may be sacrificed some power efficiencies owing to the combination of analog-and digital-assembly, but also provides cost savings potentially in integrated chip production.

Fig. 8 shows the block diagram of process transmitter 700, and this process transmitter 700 uses the measurement passage of isolating.In the illustrated embodiment of this framework, sensors A/D converter adopts the form of sigma-Delta (∑-Δ) modulator 706, and this sigma-delta modulator 706 provides high-speed data signal, for example those signals shown in Fig. 5-7.Although the form with sigma-delta modulator 706 illustrates, yet sensors A/D converter not necessarily all is sigma-delta modulator in all embodiments.In addition, formerly the A/D converter circuit shown in the figure can adopt the form of sigma-delta modulator.

Can be fed to data encoder 707 to the HSD line from sigma-delta modulator 706, data encoder 707 synthesizes individual traffic to the set of streams from sigma-delta modulator.This individual traffic passes through isolating transformer 708, and is provided for the data decoder 709 that is included in the DSPASIC 710.Demoder 709 is with the only data stream of this individual data flow point receipt.Then,decimation filter 515 data stream that each is independent in the DSP 710 is transformed into many bit words.Then each many bit words is stored in the data register 212.Although in some figure, utilize single square frame to showdecimation filter 515 anddata register 212, yet as shown in Figure 8, can use a plurality of decimation filters and a plurality of data register to realize these circuit units.

Except comprising data decoder 709, DSP 710 turns round very similarly with above-described framework.Coprocessor 215 is coupled todata register 212 equally, and is configured to the data in theregister 212 are carried out calculating.Comprise DAC register 712 alternatively, be used to store the data fromcoprocessor 215, these data are used as input and offer DAC415 after storage, are provided with the 4-20mA electric current in 250 pairs ofloop wirings 145 of controlling output circuit.In addition, as in the above-mentioned framework,SPI data register 520 is coupled tocoprocessor 215 and other assemblies, so that communicate by letter with the SPI of microprocessor 230.Microprocessor 230 comes control figure communication via digital communications module 742 equally.

In addition, optional communication check circuit 720 has been shown in DSP 710, whether this communication check circuit 720 detects and is interrupted with communicating by letter of sensor/sigma-delta modulator, so that can correspondingly notify themicroprocessor 230 of being responsible for the communication in the wiring of loop.In addition, compriseimpulse output circuit 725 alternatively among the DSP 710 in the flowmeter embodiment of process transmitter 700, thisimpulse output circuit 725 is coupling betweencoprocessor 215 and the output circuit 250.Impulse output circuit 725 controllingoutput circuit 250 produce pulse output, the frequency representation stream of this pulse output.Theaccumulator circuit 730 that is coupled to pulse output is configured to keep total flow based on pulse output.

In addition, comprise clock circuit 735 in process transmitter 700, this clock circuit 735 provides clock signal at the operation of assembly.Alternatively, can use second isolating transformer 740 to come additionally to provide clock signal, keep DSP and the isolation of measuring channel circuit simultaneously to DSP 710.Two other optional components in the process transmitter 700 comprise communication decoding circuit 745 and fault data memory circuit 750.Communication decoding circuit 745 is coupled to data encoder 707, is used for for multiple purpose (as, diagnostic function etc.) coded data being decoded.The data of the fault in fault data memory circuit 750 storage representation sensors or other assembly functions.

Fig. 9 shows the block diagram ofprocess transmitter 800, and thisprocess transmitter 800 uses the framework of the upgrading of expression foregoing structure (for example, not using the process transmitter 200,300 and 400 of HSD line or isolation characteristic at first).In this embodiment, spi bus that can be by using INT, CS method, realize communication between variables A/D converter by the HSD line or by the two.For the ease of communicating, provide function and scrambler shown in Figure 8 707similar scrambler 805 via the HSD line that provides from A/D converter 204.Also comprise isolatingtransformer 810, with DSP thatprocess transmitter 800 is provided and measure isolation between the passage.Ontransformer 810 two ends, transmit coded data.For these data are decoded, in DSP 810, comprise decoding and decimation filter circuit 815.Owing between HSD line and DSP 810, provide isolation, so also can between spi bus and DSP 810, comprise buffer circuit 811 (for example can comprise coding circuit, isolating transformer and decoding circuit).Other features ofprocess transmitter 800 are identical or similar with the feature with same numeral of the framework of describing with reference to other accompanying drawings.For this HSD being described and isolating the spendable various different frameworks of upgrading, in Fig. 9, the digital modems from Fig. 3 and 4telecommunication circuit 240 partly is shown theassembly 840 that separates, rather than combines withDAC 415 or with other assemblies in thecommunication module 420.

Although reference example embodiment has described the present invention, yet those skilled in the art will recognize that, can carry out the modification on form and the details under the premise without departing from the spirit and scope of the present invention.For example, can be the various features of different embodiment are combined at specific implementation.Although be exclusively used in architectural feature and/or method the action language description theme, yet will understand, might not be limited to above-mentioned special characteristic or action at theme defined in the appended claims.On the contrary, above-mentioned special characteristic and action are as the form of the example that realizes claim and disclosed.

Claims (18)

Translated fromChinese

1.一种过程变送器，包括：1. A process transmitter comprising:至少一个传感器，监控过程变量；at least one sensor to monitor a process variable;模拟至数字(A/D)转换器电路，耦合到至少一个传感器，并且被配置用于提供表示过程变量值的过程变量数据；an analog-to-digital (A/D) converter circuit coupled to the at least one sensor and configured to provide process variable data representing a value of the process variable;数字信号处理器(DSP)，耦合到A/D转换器电路，以接收过程变量数据，所述DSP包括协处理器，所述协处理器被配置用于从A/D转换器电路接收过程变量数据并对所述过程变量数据执行计算，以产生输出数据；a digital signal processor (DSP) coupled to the A/D converter circuit to receive process variable data, the DSP including a coprocessor configured to receive the process variable from the A/D converter circuit data and performing calculations on said process variable data to generate output data;通信电路，被配置用于控制与所述过程变送器的通信；以及communication circuitry configured to control communication with the process transmitter; and微处理器，与DSP的协处理器分离，所述微处理器耦合在协处理器与通信电路之间，以控制自DSP至所述通信电路的所述输出数据的移动，用于进行自所述过程变送器的通信。a microprocessor separate from the coprocessor of the DSP, said microprocessor being coupled between the coprocessor and the communications circuitry to control movement of said output data from the DSP to said communications circuitry for transmission from said communications circuitry communication with the process transmitter described above.2.根据权利要求1所述的过程变送器，其中，DSP的协处理器被配置用于：接收来自A/D转换器电路的中断请求，并做出响应以控制与A/D转换器电路的通信。2. The process transmitter of claim 1, wherein the coprocessor of the DSP is configured to: receive an interrupt request from the A/D converter circuit and respond to control and A/D converter circuit circuit communication.3.根据权利要求2所述的过程变送器，其中，所述过程变送器被配置用于耦合至回路布线，并且所述通信电路被配置用于控制所述回路布线上的通信，所述过程变送器还包括输出电路，所述输出电路被配置用于耦合至所述回路布线以控制所述回路布线上的4-20mA电流。3. The process transmitter of claim 2, wherein the process transmitter is configured to be coupled to loop wiring, and the communication circuit is configured to control communication on the loop wiring, the The process transmitter also includes an output circuit configured to couple to the loop wiring to control a 4-20 mA current on the loop wiring.4.根据权利要求3所述的过程变送器，其中，所述通信电路包括：4. The process transmitter of claim 3, wherein the communication circuit comprises:回路电源电路，被配置用于控制所述回路布线上的4-20mA电流；a loop power circuit configured to control 4-20mA current on said loop wiring;数字调制解调器，耦合至所述输出电路，并且被配置为使用数字通信协议控制所述输出电路在所述回路布线上进行通信；以及a digital modem coupled to the output circuit and configured to control the output circuit to communicate over the loop wiring using a digital communication protocol; and数字至模拟转换器(DAC)，耦合至所述输出电路，并且被配置用于向所述输出电路提供模拟信号，从而控制所述回路布线上的4-20mA电流。A digital-to-analog converter (DAC) coupled to the output circuit and configured to provide an analog signal to the output circuit to control a 4-20 mA current on the loop wiring.5.根据权利要求4所述的过程变送器，其中，所述数字通信协议是HART通信协议。5. The process transmitter of claim 4, wherein the digital communication protocol is a HART communication protocol.6.根据权利要求4所述的过程变送器，其中，所述DSP耦合至所述DAC以向所述DAC提供数字值，用于控制所述模拟信号并从而控制所述回路布线上的4-20mA电流，并且，所述微处理器耦合至使用所述数字通信协议来控制所述回路布线上的数字通信的所述数字调制解调器。6. The process transmitter of claim 4, wherein the DSP is coupled to the DAC to provide digital values to the DAC for controlling the analog signal and thereby controlling the 4 on the loop wiring. -20mA current, and said microprocessor is coupled to said digital modem using said digital communication protocol to control digital communication on said loop wiring.7.根据权利要求6所述的过程变送器，其中，所述DSP还包括所述通信电路的所述DAC。7. The process transmitter of claim 6, wherein the DSP further comprises the DAC of the communication circuit.8.根据权利要求7所述的过程变送器，还包括：串行外围接口(SPI)至控制器局域网(SPI至CAN)通信电路，耦合至所述微处理器并接收来自所述微处理器的SPI通信。8. The process transmitter of claim 7, further comprising: serial peripheral interface (SPI) to controller area network (SPI to CAN) communication circuitry coupled to said microprocessor and receiving device SPI communication.9.根据权利要求8所述的过程变送器，还包括通信模块，所述通信模块包括所述数字调制解调器和所述SPI至CAN通信电路。9. The process transmitter of claim 8, further comprising a communication module comprising said digital modem and said SPI to CAN communication circuit.10.根据权利要求9所述的过程变送器，还包括：诊断A/D转换器，耦合至所述微处理器并接收来自所述微处理器的SPI通信。10. The process transmitter of claim 9, further comprising a diagnostic A/D converter coupled to said microprocessor and receiving SPI communications from said microprocessor.11.根据权利要求10所述的过程变送器，其中，所述通信模块还包括所述诊断A/D转换器。11. The process transmitter of claim 10, wherein the communication module further includes the diagnostic A/D converter.12.根据权利要求9所述的过程变送器，其中，与所述至少一个传感器耦合的所述A/D转换器电路仅包括模拟组件，所述A/D转换器电路的模拟组件被配置用于通过与所述DSP耦合的高速数据(HSD)数据线路对来提供表示过程变量数据的输出，其中，所述DSP还包括抽取滤波器电路，所述抽取滤波器电路耦合至所述高速数据线路对，并且被配置用于将所述A/D转换器电路的输出转换成表示所述过程变量数据的多比特数字字。12. The process transmitter of claim 9, wherein the A/D converter circuit coupled to the at least one sensor includes only analog components, the analog components of the A/D converter circuit being configured for providing an output representing process variable data over a pair of high speed data (HSD) data lines coupled to the DSP, wherein the DSP further includes a decimation filter circuit coupled to the high speed data A pair of wires and configured to convert the output of the A/D converter circuit into a multi-bit digital word representing the process variable data.13.根据权利要求12所述的过程变送器，还包括混合式专用集成电路(ASIC)，所述混合式ASIC包括所述通信模块以及所述A/D转换器电路的模拟组件。13. The process transmitter of claim 12, further comprising a hybrid application specific integrated circuit (ASIC) comprising the communication module and analog components of the A/D converter circuit.14.根据权利要求13所述的过程变送器，还包括数字DSP ASIC，所述数字DSP ASIC包括所述DSP和所述微处理器。14. The process transmitter of claim 13, further comprising a digital DSP ASIC comprising said DSP and said microprocessor.15.根据权利要求12所述的过程变送器，还包括组合的模拟和数字ASIC，所述组合的模拟和数字ASIC包括所述DSP、所述微处理器、所述通信模块以及所述A/D转换器电路。15. The process transmitter of claim 12, further comprising a combined analog and digital ASIC comprising said DSP, said microprocessor, said communication module, and said A /D converter circuit.16.根据权利要求12所述的过程变送器，其中，所述A/D转换器电路包括西格玛-德尔塔转换器电路，所述过程变送器还包括：16. The process transmitter of claim 12, wherein the A/D converter circuit comprises a sigma-delta converter circuit, the process transmitter further comprising:数据编码电路，耦合至所述西格玛-德尔塔转换器电路，并将所述西格玛-德尔塔转换器电路的输出编码成单个数据信号；a data encoding circuit coupled to the sigma-delta converter circuit and encoding the output of the sigma-delta converter circuit into a single data signal;数据解码电路，位于所述DSP中并耦合至所述抽取滤波器电路，所述数据解码电路将所述单个数据信号解码成多个数据信号，并将所述多个数据信号提供给所述抽取滤波器电路，以转换成表示所述过程变量数据的多比特数字字；以及a data decoding circuit located in the DSP and coupled to the decimation filter circuit, the data decoding circuit decoding the single data signal into a plurality of data signals and providing the plurality of data signals to the decimation filter circuitry to convert into multi-bit digital words representing said process variable data; and隔离变压器，耦合在所述数据编码电路与所述数据解码电路之间。An isolation transformer is coupled between the data encoding circuit and the data decoding circuit.17.根据权利要求16所述的过程变送器，还包括：17. The process transmitter of claim 16, further comprising:时钟电路，向所述西格玛-德尔塔转换器以及向所述数据编码电路提供时钟信号；以及a clock circuit that provides a clock signal to the sigma-delta converter and to the data encoding circuit; and时钟信号隔离变压器，耦合在所述时钟电路与所述DSP之间，用于向所述DSP提供所述时钟信号并且同时将所述DSP与所述时钟电路隔离。A clock signal isolation transformer, coupled between the clock circuit and the DSP, is used to provide the clock signal to the DSP and simultaneously isolate the DSP from the clock circuit.18.根据权利要求2所述的过程变送器，其中，所述通信电路包括无线通信模块。18. The process transmitter of claim 2, wherein the communication circuitry includes a wireless communication module.

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